Roasting-furnace



(No Modem 2 sheets-sheet 1.

H- G." GRITTINGER. Roasting Furnace. No. 242,769. Patented June I4, 1881..

I I ll WITNESSES m mv sirrbn ATTORNEY N. PETERS. FhoIo-Mhognpher. Wanhingtuvn D. C.

UNITED STATES PA ENT OFFICE.

HENRY O. GRITTINGER, OF CORNWALL, PENNSYLVANIA.

ROASTlNG-FURNACE.

SPECIFICATION forming part of Letters Patent No. 242,769, dated June 14, 1881.

To all whom it may concern Be it known that I, HENRY G. GRITTINGER, of Cornwall, in the county of Lebanon and State of Pennsylvania, have invented certain new and useful Improvements in Roasting-Furnaces; and I do hereby declare the following to be a full, clear, and'exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being had to the accompanying drawings, which form part of this specitication.

My invention relates to an improvement in roastingfurnaces to be employed in expelling sulphur or like substances from iron or other ores with which they may be combined.

The object of my invention is to provide a furnace of the character designated, wherein both lump and pulverized ore may be simultaneously treated to have the volatile substances in combination with them perfectly eliminated, and this with the consumption of the minimum amount of fuel.

A further object of my invention is the construction of a roasting-furnace with a view, if desired, of partially fusing or clinkering the fine ore, and at the same time have it so arranged that the clinkers can be removed with ease and without obstrnctin g the chutes through which the roasted ore is withdrawn, thereby avoiding the collection of the pulverized ore, &c., in the draft-openings of the furnace, which causes the retardation of the combustion of the fuel, the ore to be very indifferently roasted, and the capacity of the furnace to be decreased.

WVith these objects in view my invention consists in certain details of construction and combinations of parts, as will hereinafter be described, and pointed out in the claims.

In the accompanying drawings, Figure 1 is a front View of a roasting-furnace constructed in accordance with my invention. Fig. 2 is a View in vertical central section thereof; and Fig. 3 is a view, in cross-section, through the base of the star-shaped cone located within the cylinder of the furnace.

A represents the cylindrical top or shell of the furnace, into which the ore and fuel are introduced through its upper extremity. This shell may be of any approved form of construction. It may, for example, assume the form shown in the drawings, where it is provided Application filed February 26, 1881. (No model.)

pair of columns E, and, in addition to their primary use, serve to allow the interior of the furnace to be penetrated and admit an extra supply of air to the support of combustion within the cylinder. Said chutes consist of side plates, H H, inclined bottom plates, I, and are also provided with gates operated by levers S and rods T. The inner ends of plates H H are respectively attached to the inwardlyinclined faces L of the columns E, and the outer ends of said plates are arranged to approach each other to form a channel, the terminus of which extends a sufficient distance beyond the masonry upon which the whole furnace is mounted to allow the blast-furnace charging-barrows to be rolled under and filled directly from the chutes. The bottom plates, I, of these chutes have their inner edges impinged against one of the four sides of the cone in such manner as to form a continuous inclined surface therewith. The opposite edges of the plates I are bent to form upwardly-extending flanges N, to the inner faces of which the lower edges of the plates H H are bolted. A strengthening-plate, O, flanged at each end and bolted to the upper edges of the plates H H, is designed to prevent them from being forced apart by the pressure of the ore, to which maybe added the pressure of the weight of the ore above, and prevents the ore from discharging itself over the gates. Bearings pivoted to the inner faces of the upper edges of the plates offer pivotal adjustment for a cross-bar, Q, provided with downwardly-extending grate-bars R, which retain the ore in the chutes until it is desired to withdraw it. These gates, consisting of cross-bar Q and grate-bars R, are operated to be opened and closed through levers S and rods T.

Havin g thus described the external construction of my improved'furnace, I will now describe its internal arrangement, which is designed particularly to effect an equal division of the ore among the four discharging-chutes described. With this end in view I have provided a pyramidal star-shaped cone, 0, each of the points U of which projects toward one of the four supporting-columns D. The bottom plates, I, of the chutes, before described as extending between two contiguous columns and having their inner edges abutting respectively against one side of the cone, will continue at a lesser inclination the trough or channel formed between the two adjacent sides of contiguous points thereof. The said cone is mounted on suitable supporting devices of masonry or other suitable supporting structure in such position that the point thereof, which extends upwardly into the cylinder, will be situated in its exact center, so as to make anequaldivision of the ore as it descends from above into the four channels which lead to the four chutes, as mentioned. The cone is provided with a central draft, A, for an air-current, and with a conical cap, B, fitting over the top thereof, to deflect said current and diffuse it more equably through the cylinder.

The abundant supply of atmospheric air in roasting is indispensable to a perfect elimination of the sulphur and other Volatile substances which it is desired to expel from the ore, and in view of this fact I have made threefold provision for the admission of air into my furnace-namely, through the central draft in the cone, through the perforations O in the boshes of the cylinder, and through the widexnouthed chutes. By means of this threefold supply of air the fire can be sustained at the top of the ore in the cylinder, and the amount of fuel used is reduced thereby to a minimum. It is desirable to maintain the fire at the top of the ore in the cylinder, if possible, as when the sulphurous vapors eliminated from ore in the bottom of the furnace are obliged to force their way through a mass of superincumbent ore which is often wet it will be condensed in the ore, and considerably more fuel will be necessary to revolatilize it before it leaves the furnace. When the fire can be maintained at the top of the ore the condensation of vapors caused by incoming supplies of wet and cold ore is too slight to be of particular moment. Again, the roasting ore in the cylinder, which is, of course, intensely heated, will take a large amount of oxygen from the currents of air passin g through the furnace, and thus become partially oxidized, which will, of course, very materially decrease the expense of its reduction in the blast-furnace.

It is, of course, apparent that I may use cones having more than four points, but in instance of such use the number of chutes and supporting columns must necessarily be increased in the same ratio.

I am aware that the bottom of a limekiln has been provided with inclined metal supportingplates leading from the center of the kiln, and

forming the bottoms of the trough-shaped discharge-chutes, for causing the material to be directed from the center of the kiln to the discharge-openin gs but in such construction there is no air-inlet to the center of the kiln, and, further, the bottoms of the chutes rest upon the base of the kiln, thereby preventing a discharge of the material directly into barrows.

I am also aware that limekilns have been provided at their lower ends with a central inlet for carbonic-oxide or blast-furnace gas, the upper end of said inlet being encircled by a conical plate, over which is located a hood for deflecting the gas. In this construction an annular converging space is formed between the walls of the kiln and conical plate surrounding the gas-inlet. The material enters this annular space, and from thence is conveyed to the discharge-openin gs.

I am also aware that furnaces have been provided with a cone extending upwardly into the bottom thereof, an enlarged annular space being formed around the cone for spreading the material, and openings formed in the cone for the escape of air and combustible gases; hence I would have it understood thatl make no claim to any of the forms of construction above referred to.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a roasting-furnace, the combination, with a star-shaped cone located within the furnace, of discharge-chutes having their sides attached to adjacent supporting-columus, and bottom plates arranged to abut against the base of the cone, substantially as set forth.

2. In a roasting-furnace, the combination, with a star-shaped cone located within the cylinder or ore-receptacle, the ridges of said cone extending from its apex to the supporting-columns, and its portions between the ridges made converging or trough-shaped, of dischargechutes consisting of side plates secured to two adjacent columns, and the inclined bottoms of the chute fitted to the converging or troughshaped portions of the cone, substantially as set forth.

3. In a roasting-furnace, chutes consisting, essentially, in the combination, with side plates respectively attached to adjacent supportingcolumns, of a bottom plate abutting against the base of one face of the central star-shaped cone,a strengthening-plate clasping the upper edges of the side plates, and gates consisting in bars pivotallysecured between the two side plates, grate-bars depending from the said pivoted bars, and levers and handles to operate the said gates, substantially as set forth.

In testimony that I claim the foregoing I have hereunto set my hand this 15th day of February, 1881.

HENRY O. GRITTINGER.

Witnesses:

GEO. D. RIsE, LEWIS REHR. 

